Virage: Will 1 bad hall effect sensor cause just a bog off idle?

[Bluedmax]

Hi All,

Needing some help on my 2001 Virage. It's been a long road and I can't get to the finish line. Purchased the ski new in 2001, been running great for 20 years. Last year had to replace the engine, purchased a reman from SBT. Engine ran fine but found out the exhaust manifold surfaces between the 2 cylinders was not machined correctly, causing the manifold bolts to come loose or break. Pulled the engine and sent back to SBT for warranty, they sent replacement engine #2. Machining all looks good, but now I haven't been able to get this one to run right. It will start on the button, idles great, then has the infamous bog (sometimes dies) when you hit the throttle. Doesn't seem to be consistent either, sometimes bogs worse than other times. If I feather through the throttle it will run good at high rpm but the power band comes on late and takes a lot of throttle to get it there. I haven't wanted to keep giving it wide open throttle because 1) the 2nd replacement isn't completely broken in yet and 2) something is obviously not right. I've gone through everything I can think of... rebuilt carb and fuel pump (SBT kit), gone through carb again and again like 10 times, double checked jet sizes and locations, pop off set at 19 (spec 18-20), lever height set at 1.5mm per spec, low screw 1-3/4 out per spec, pressure checked fuel pump diaphragm, accel pump works, pressure tested fuel lines, strainer assembly, shut off valve, relief valves, pressure checked crankcase pressure (with intake and exhaust manifolds on) at 9psi for 5 minutes, new correct NGK resistor spark plugs, sprayed chemtool on all external seal areas to check for leaks (only thing I could find was a slight RPM change through throttle shaft area, set idle at 1300, made sure oil injection cable is adjusted properly. If anyone has any comments or suggestions with the above, I'm all ears.

After all that and no luck, I've now started checking the ignition side of things and have some concerns...

• Disconnect plug wire caps from each spark plug and check continuity from inside of both spark plug caps. Spec between the 2 wires = 8000, my reading = 12000. Is this too high and I need new wires?
• Check continuity from inside spark plug caps to ground. Spec = open, both are ok.
• Open electrical box and check the primary side resistance of the ignition coil tabs (where plug wires connect). Spec = 0.35, my reading = 0.50. Think I'm ok here?
• Check secondary side resistance of the ignition coils, coil tab to each secondary lead. Both check out ok.
• Measure the resistance of each plug wire: short wire spec = 3700ohms, my reading is 6500. Long wire spec = 4540 ohms, my reading = 3100.
• Check resistance of the coil without the plug wires installed. Spec = 1200-1600ohms, my reading = 2900.
• Performed hall effect sensor test: green wire is triggering, red wire I cant get anything.

Seems to me I have a bad hall effect sensor for sure, but would the engine even run like this?? Again it fires right up, idles great, runs good at high rpm, and only has a bad bog off idle. Seems to me if a hall sensor was bad, the engine would run much worse. Sorry for the long post but this is a culmination of my frustrations. Thanks in advance for the help!!

[Bluedmax]

Anyone have any thoughts??
My biggest question right now is... Is it possible the ski can still start and idle good and run decent with only 1 hall effect sensor working?

[casey67]

According to you, you checked everything else.
Once you find parts that test bad, they need to be replaced, regardless of someone's opinion.

[K447]

Anyone have any thoughts??
My biggest question right now is... Is it possible the ski can still start and idle good and run decent with only 1 hall effect sensor working?

The idle RPM at 1300 was set with the hull in the water, correct?

This is a two cylinder carb engine?

You can install inline spark testers on all the spark plugs. Then you can see if one cylinder is losing (or gaining) spark at certain RPM.

Your ohm checks of the spark plug wires and the Gen III ignition coil do seem out of range. Confirm the 'factory specs' for the Gen III two cylinder carb engine with another source/manual.

http://polarispwcknowledge.shorturl.com/electrical/ignition-system-1

http://greenhulk.net/showthread.php?t=97491&p=1110103&viewfull=1#post1110103

Check for spark with the inline testers.
If one cylinder consistently does not have spark you can swap 'channels' through the CDI to see if the problem moves or stays with the same cylinder. Basically swap the Hall Effect sensor wires into the CDI and see if the problem moves to the other cylinder.

You may want to replace the spark plug wires and ignition coil as a sanity check.

[Bluedmax]

Thanks Casey. I feel like I'm second guessing everything I do at this point, so just looking for some confirmation I guess. I also don't understand why the ski would still be running as well as it does if only 1 cylinder is firing?? It looks like ebay is the only place to get a replacement stator these days. Any suggestions on what to get? It looks like there's some new and most used for prices that range from $100-500 (used is more than new??)

[K447]

New magneto stators for Polaris carb PWC are mostly aftermarket. Mostly (all?) China sourced. Reliability of the aftermarket stators has been hit and miss. Some work, some are non-functional right out of the box. Even though the basic coil ohm checks seem to be within spec.

Good used genuine Polaris OEM stators (Gen III) made by PVL tend to work as expected.

For a while there was a supply of PVL recently produced 'Polaris red engine stators' (sold through a couple of well known Polaris parts sellers) but those may be mostly gone/sold by now?

The genuine PVL stators are preferred over aftermarket and the supply is limited, hence the higher prices.

[[email protected]]

Try to run the engine on one cylinder, then the other. If the hall effect sensor is bad, one of the 2 cylinders wont run even though you see spark on both cylinders. The ignition system fires at the top and bottom or the stroke so see if you can run on one cylinder. 2. Check fuel pickup in the tank or check fuel flow from the pump to make sure you are not starving the engine.

[Bluedmax]

Thanks K447.
Yes I set the idle at 1300 in the water. The service manual says 1350 +/- 100
2 cylinder (red) carb engine
A couple weeks ago during my testing I had installed 2 inline spark testers, one on each plug. It was during the day and the sun was bright, but it looked like both were sparking good. I wasn't sure if this would give me an accurate reading though as I understand both plugs will fire both cylinders every stroke. I'll try again at night when I can see better if 1 cylinder is cutting in and out as you suggest.
The first link appears to focus on ignition system identification. It's my understanding I have the most recent Gen III.
The values in the second link appear to be the similar to my manual with the exception of the individual spark plug wire ohms values. My reading on the long wire matches the spec in the link (3100), however my short wire is still way off (6500 reading vs 2374 spec in the link (even lower than the 3700 spec in my manual). I'll plan on buying new wires for sure. I'm thinking the coil is fine, but might end up doing that also. I need all the sanity I can get right now!

[Bluedmax]

New magneto stators for Polaris carb PWC are mostly aftermarket. Mostly (all?) China sourced. Reliability of the aftermarket stators has been hit and miss. Some work, some are non-functional right out of the box. Even though the basic coil ohm checks seem to be within spec.

Good used genuine Polaris OEM stators (Gen III) made by PVL tend to work as expected.

For a while there was a supply of PVL recently produced ‘Polaris red engine stators’ (sold through a couple of well known Polaris parts sellers) but those may be mostly gone/sold by now?

The genuine PVL stators are preferred over aftermarket and the supply is limited, hence the higher prices.

That's what I was afraid of. It looks like there might be a new "Genuine Polaris" one on ebay for $250... ouch!
I'll obviously buy one if I need to, but just trying to confirm mine is for sure bad first.
I'm open to direction if there's some Polaris sellers that can supply a good one.

[Bluedmax]

Try to run the engine on one cylinder, then the other. If the hall effect sensor is bad, one of the 2 cylinders wont run even though you see spark on both cylinders. The ignition system fires at the top and bottom or the stroke so see if you can run on one cylinder. 2. Check fuel pickup in the tank or check fuel flow from the pump to make sure you are not starving the engine.

So if I unplug a spark plug wire and there's no change in the way it runs, that would by my problem cylinder.
If I unplug a spark plug wire and there is a change, that cylinder was working.
I've done a visual inspection of the pickup in the tank (while still installed) and seemed to be good.
Is there a specific way to check actual fuel flow? I followed the procedure in the manual by taking off the return hose from the carb (at idle) to verify there is a little fuel returning in the system.
I have also drained all the fuel lines (to perform a system pressure test) and was able to prime the lines again just fine.
Do you think these tests are sufficient? I guess these could all prove the fuel supply is ok at idle but still starving when throttling up?

[K447]

So if I unplug a spark plug wire and there's no change in the way it runs, that would by my problem cylinder. …

With the wasted spark system and double ended ignition coil the unplugged spark plug wire end must be grounded to the engine to ensure the other plug can still spark properly.

Essentially you just need to ground the plug wire connection at the plug to do a ‘dropped cylinder’ test.

[Bluedmax]

With the wasted spark system and double ended ignition coil the unplugged spark plug wire end must be grounded to the engine to ensure the other plug can still spark properly.

Essentially you just need to ground the plug wire connection at the plug to do a ‘dropped cylinder’ test.

Yes, got it! There's a double ground post bolted to the end of the coolant rail that I attach the wires to when disconnected.

[Bluedmax]

After some more checks, it looks like I'm chasing down 2 separate problems... both ignition and fuel.
I double checked my hall effect sensor test and discovered I messed up the first time. What I thought was the red wire not sending a signal during my ohms test, turned out to be that I tested the red/purple wire by mistake (I didn't see the purple stripe the first time because it was on the inside of the wire loom). After checking the "correct" red wire, I have a good signal on both wires now.
The problem on my ignition side appears to be the short spark plug wire (the one I tested with high resistance). Turns out the inner core wire was cracked and brittle at the spark plug end. I was able to cut back (several times), find where the core wire was good enough to reattach my terminal and get my ohms back down to spec, then connect back to the plug for continued testing. I'll be ordering a new set of wires!

I still have a fuel problem. It looks to me that while the accel pump is squirting fuel when hitting the throttle "most" of the time, it's not squirting "every" time I hit the throttle. If I "pump" the throttle a couple times it seems to prime the system better and I see a better squirt of fuel, the engine will respond better for a bit, but then go back to bogging. I disassembled the accel pump system (again) but can't seem to get any improvement. There always seems to be a good amount of fuel in both the jet block and accel pump diaphragm areas when I disassemble everything. The diaphragm and oring appear to be good, I ran cleaner through the check ball and spring in the carb body, I checked the condition of the hose between the body and nozzle, and I disassembled the nozzle end and cleaned it. Not sure where to go from here. Is it possible one of the check balls may not be sealing properly or completely all the time? Thx again.

[K447]

- 2 separate problems...

This is why I always advise to not assume there is only one problem occurring, or that only one thing needs fixing to get a problem solved.

Often, especially with these older watercraft, there are multiple problems and perhaps multiple causes for some of those problem. This can make for confusing or seemingly conflicting diagnostics at times.

Be methodical. Recheck your work when a result seems incorrect or just suspect.

With electrical, you can have a wiring error and a weak battery, and a bad component.

With the fuel system you can have an air leak and a fuel leak and a hose connection swapped. And a clogged carb filter. And water in the fuel tank.

And so on

[Bluedmax]

This is why I always advise to not assume there is only one problem occurring, or that only one thing needs fixing to get a problem solved.

Often, especially with these older watercraft, there are multiple problems and perhaps multiple causes for some of those problem. This can make for confusing or seemingly conflicting diagnostics at times.

Be methodical. Recheck your work when a result seems incorrect or just suspect.

With electrical, you can have a wiring error and a weak battery, and a bad component.

With the fuel system you can have an air leak and a fuel leak and a hose connection swapped. And a clogged carb filter. And water in the fuel tank.

And so on

Yeah no kidding! Always easier said than done right?
It's as if the pump only squirts consistently on a more aggressive pull of the throttle and sometime dribbles or no spray on a light pull.
About the only thing I haven't done yet is disassemble the check ball assembly in the housing to clean / inspect. Is there a way to do this? I've heard those can have a plastic ball that might need to be changed out to brass?